Hydraulic air injector



July 5, 1966 L. BRYAN 3,

HYDRAULIC AIR INJECTOR Filed Dec. 4, 1963 T l I l CK |9 I T V I 22 LIJ 2 5 l I l0 12 VI? f FROM PUMP 20 INVENTOR LLOYD BR YAN ATTORNEY United States Patent O 3,259,067 HYDRAULIC AIR INJECTOR Lloyd Bryan, 1780 Atlas Park Road, Napa, Calif. Filed Dec. 4, 1963, Ser. No. 327,917 2 Claims. (Cl. 1036) The present invention relates to an apparatus for automatically maintaining the required head of air in a pressurized water tank of water systems.

The usual home water system pressure is'developed in the lines by pumping water from a water supply into a tank at the top of which is maintained a head of air. As the water in the tank rises under pressure from the pump, the air head is compressed. When a line leading from a tank is opened, the body of air under pressure is effective to force the water out under pressure. With respect to pressure, the tank is usually provided with a switch which turns the pump motor on at around 20 pounds per square inch pressure in the tank and turns the same oil? when the pressure reaches about 40 pounds.

With the advent of the new automatic washers in homes, water pressures are being increased above 40 pounds and a primary object of the present invention is to provide an apparatus in which a greatly increased pressure can be obtained without unduly increasing the size and cost over standard equipment.

A further object of the present invention is to provide an apparatus of the type described wherein maintenance and repair are at a minimum due to the accessibility of the various parts of the assembly.

Other objects and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing showing a flow diagram of the present hydraulic air injector.

Referring to the drawing in detail, numeral designates a receiver tank which is typical of the usual pressure tank associated with home water systems. On top of the tank and diagrammatically illustrated at 11 is a pressure switch which controls the operation of an electric motor connected to a pump for pumping water into the tank through a line 12. Pressure is developed in the tank 10 by maintaining a head of air 13 at the top thereof to force the water out of the tank in a manner to be described.

My improved device, indicated by the numeral 14, is adapted for mounting on the side of the tank. As shown, the same comprises a pair of vertically disposed cylinders 15 and 16 receiving pistons 17 and 18 connected by a connecting rod 19. A stop 18', secured to the upper surface of piston 18, limits the upper movement in cylinder 16. A stop 20 secured to the lower end of piston 17 limits the downward movement of piston 17 as shown in the drawing, permitting water flowing through line 12 to flow to the base of piston and force same to a point adjacent the top of the cylinder 15 as shown in dotted lines on the drawing. A pipe 20' leads from the upper end of cylinder 15 to the tank 10 for flow of liquid to and from line 12 to the tank. Also extending from the cylinder at a point slightly below half the height thereof and connecting with the pipe 20 is a second pipe 21, having a check valve 22 mounted therein. As indicated in the drawing, water from line 12 flows to the bottom of piston 17, forcing it to the dotted line position shown, through pipe 21, check valve 22, to pipe 20' and into the tank 10. Interposed between the line 12 and the cylinder 15 is a return pipe 23 and check valve 24 for feeding water from the tank back to line 12 to service pipe 25.

At the upper end of piston 16, there is provided a pipe 26 connecting the upper end of cylinder 16 with the upper end of the tank 10. A check valve 27 is "ice mounted in pipe 26 permitting flow of air and water from the cylinder 16 to the tank 10. A second pipe 28 extends from the upper end of the cylinder 16 and has a check valve 29 mounted therein to provide air from the atmosphere into the top of the cylinder 16. Bypasses 30 and 30' are formed at the lower and upper ends of the cylinder 16 for a purpose to be described.

The operation of the invention is as follows:

When the pump, not shown, is in operation, water is forced through the line 12 into the service line 25 or into the tank 10. If water is being drawn to service, it will be taken off the line prior to entering the injection apparatus 14. Otherwise, it will flow to the base of iston 17 and force it to the top of cylinder 15 as shown in dotted lines. The connecting rod 19 will also move piston 18 to the top of cylinder 16. In this position, the water from line 12 will pass through check valve 22 into the receiver tank 10. Also water and air trapped above piston 18 will be forced through check valve 27 into the receiver tank.

After the tank has been filled to the point where the pressure switch 11 shuts off the pump or if more water is drawn to service than the pump supplies, a reverse flow will be introduced. Water departing the receiver tank through pipe 20' Will force piston 17 down to the bottom of cylinder 15 and pass through line 23 and check valve 24 to service 25. The movement of piston 17 downward will move piston 18 downward, thereby drawing air at atmospheric pressure through check valve 29 into cylinder 16. As piston 18 reaches the bottom of cylinder 16, it will open up bypasses 30 to allow water at receiver pressure into the bottom of cylinder 16 to fill cylinder 16 with water and pressurize the trapped air. The water washes the air out of cylinder 16 on each stroke of piston 18. When the tank pressure is reduced again to the minimum range, the pump will start again automatically and as the water starts to flow back into the receiver, piston 17 will be forced up again to repeat the injection cycle.

The upper bypasses 30 are provided so that piston 18 will become hydrostatically balanced at the extreme top of its stroke to assure that piston 17 is relieved of its load in order to clear the passageway into bypass when in the upper position.

From the foregoing, it will be apparent that the present apparatus is simple and inexpensive to manufacture, positive in operation, easy to maintain, and well adapted to accomplish the objects set forth. While I have shown a preferred embodiment of the invention, it will be ob vious to those skilled in the art that minor changes may be made without departing from the spirit of the invention.

Having thus described the invention, what is claimed 1. A hydraulic air injector for the pressure tank of a water system or the like comprising a water tank, a water line leading into said tank, a pipe to service mounted in said line, an injection apparatus interposed in said line, between said pipe and said tank, said apparatus comprising a pair of vertically spaced cylinders, connected pistons mounted in said cylinders, a valved passageway from the lower cylinder to the water line for admitting water to said tank when the piston in said cylinder is in its fully raised position and a return valved passageway from said cylinder to said Water line for admitting water to said line and to the service pipe when the piston is in its fully lowered position, said upper cylinder having a valved passageway extending into the upper portion of the tank for admitting air and water into the top of the tank, a second valved passageway at the upper end of the upper cylinder for admit-ting air to the upper end of the upper 3 cylinder, and a bypass formed at the lower end of the upper cylinder.

2. Apparatus as defined in claim 1, in which the cross sectional view of the lower cylinder is larger than the cross sectional area of the upper cylinder.

1,941,766 1/1934 Thom 1036 9/1940 Hartmann 103-6 10 4 2,362,586 11/1944 Ruth 1036 2,447,173 8/1948 Gordon 1036 2,578,050 12/1951 Deters 230-52 FOREIGN PATENTS 885,873 12/1961 Great Britain.

SAMUEL LEVINE, Primary Examiner.

DONLEY J. STOCKING, Examiner.

W. L. FREEH, Assistant Examiner. 

1. A HYDRAULIC AIR INJECTOR FOR THE PRESSURE TANK OF A WATER SYSTEM OR THE LIKE COMPRISING A WATER TANK, A WATER LINE LEADING INTO SAID TANK, A PIPE TO SERVICE MOUNTED IN SAID LINE, AN INJECTION APPARATUS INTERPOSED IN SAID LINE, BETWEEN SAID PIPE AND SAID TANK, SAID APPARATUS COMPRISING A PAIR OF VERTICALLY SPACED CYLINDERS, CONNECTED PISTONS MOUNTED IN SAID CYLINDERS, A VALVED PASSAGEWAY FROM THE LOWER CYLINDER TO THE WATER LINE FOR ADMITTING WATER TO SAID TANK WHEN THE PISTON IN SAID CYLINDER IS IN ITS FULLY RAISED POSITION AND A RETURN VALVED PASSAGEWAY FROM SAID CYLINDER TO SAID WATER LINE FOR ADMITTING WATER TO SAID LINE AND TO THE SERVICE PIPE WHEN THE PISTON IS IN ITS FULLY LOWERED POSITION, SAID UPPER CYLINDER HAVING A VALVED PASSAGEWAY EXTENDING INTO THE UPPER PORTION OF THE TANK FOR ADMITTING AIR AND WATER INTO THE TOP OF THE TANK, A SECOND-VALVED PASSAGEWAY AT THE UPPER END OF THE UPPER CYLINDER FOR ADMITTING AIR TO THE UPPER END OF THE UPPER CYLINDER, AND A BYPASS FORMED AT THE LOWER END OF THE UPPER CYLINDER. 